2. MOLECULAR IMAGING CORE PI: Michael Garwood, PhD; co-PI: Jerry Froelich MD; Co-I Gulin Oz CORE AIM Magnetic resonance spectroscopy (MRS) and positron emission tomography (PET) are two major modalities of molecular imaging, which allow direct assessment of metabolite and tracer concentrations in brain in vivo. They are critically important in studies of neurochemistry, brain function and perfusion, and can provide surrogate markers to detect brain diseases, to monitor disease progression, and to evaluate the effectiveness of novel therapies. With MRS, the richness of the biochemical information and the accuracy of metabolite quantification are strongly linked to spectral quality. In this regard, the ultrahigh field MRI/MRS systems in the CMRR, particulariy the new 16.4 T rodent capable system, the 9.4 T animal system with [13]C DNP hyperpolarizer, the 7T human systems, and the future 10.5 T human system, offer major advantages. In particular, they provide superior signal-to-noise ratio (SNR) and spectral resolution, for improved reproducibility in the detection and quantification of brain metabolites. In addition, brain scans with human PET/CT, microPET/CT, and Neuro SPECT are now available in the recently expanded CMRR.